Benchmark: loop over Set conditionally vs non-conditionally

Script Preparation code:

var sets = [
  new Set(),
  new Set(new Array(15).fill(null).map((_,i) => i)),
  new Set([null]),
  new Set([1]),
  new Set([1,2,3]),
  new Set([]),
  new Set(new Array(33).fill(null).map(() => Math.random()))
];

Tests:

size check
let count = 0; while (sets.length) { const set = sets.pop(); if (set.size) { for (const value of set) { count += value; set.delete(value); } } }
no size check
let count = 0; while (sets.length) { const set = sets.pop(); for (const value of set) { count += value; set.delete(value); } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
size check
no size check

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

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Let's break down the provided benchmark and its test cases.

**Benchmark Definition**

The benchmark tests two approaches to iterating over a Set in JavaScript:

1. **Conditionally checking `set.size`**: This approach checks if the set has any elements (i.e., its size is greater than 0) before starting the iteration.
2. **Not checking `set.size`**: In this approach, the iteration proceeds regardless of whether the set contains elements or not.

**Pros and Cons**

* **Conditionally checking `set.size`**:
	+ Pros: Can improve performance when iterating over a large number of empty sets, as it avoids unnecessary iterations.
	+ Cons: May introduce additional overhead due to the check, which could be negligible for small sets or sets with non-empty elements.
* **Not checking `set.size`**:
	+ Pros: Avoids potential overhead from the size check, making it potentially faster for large datasets or empty sets.
	+ Cons: May lead to unnecessary iterations over large numbers of empty sets, wasting computational resources.

**Library and Special JS Features**

There is no library explicitly used in this benchmark. However, JavaScript's built-in `Set` data structure is being utilized, which provides efficient membership testing and iteration capabilities.

**Special JS Feature**

The `for...of` loop is being used to iterate over the sets, taking advantage of its ability to automatically handle iteration over iterable objects like Sets.

**Other Alternatives**

Alternative approaches could include:

1. Using traditional `for` loops with indexing (`set[0]`, `set[1]`, etc.) instead of `for...of`.
2. Utilizing a library like Lodash, which provides utility functions for working with sets and collections.
3. Implementing custom iteration logic using recursion or other approaches.

For this specific benchmark, the primary choice between conditionally checking `set.size` and not checking it at all is driven by performance considerations, particularly when dealing with large datasets or empty sets.

Related benchmarks:

loop over Set conditionally vs non-conditionally (version: 0)

when a Set() may or may not contain entries, is it more efficient to check Set.size before starting a for...of loop or does it not matter?

Comparing performance of: size check vs no size check

Created: 4 years ago by: Guest

Jump to the latest result

size check

no size check

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):